1) Turn OFF the push email option to OFF when you are not using that option in you iPhone.
2) Turn down the brightness to 50%.
3) Turn OFF the Bluetooth – Switch OFF the Bluetooth option if you are not using it. If the Bluetooth headsets are not used and also the data transfer using Bluetooth is not done often u can save a lot of battery.
4) Persistently don’t check mails- Persistent mail checking will drain a lot of your IPhone battery though you change that email settings to manual so limit the checking of mails.
5) Turn OFF vibration unless using it in silent mode.
6) Turn OFF the GPS.
7) Avoid keeping your iPod connected to wireless network.
8 ) Don’t play 3D games all the day.
9) Don’t keep the WiFi option on all the day – Turn off the WiFi option if you are not at home. That is whenever you are in the outside where you know that you will have WiFi access turn off the WiFi on the iPhone .this is increase battery life.
10) Don’t keep 3G ON until you need them.
11) Turn OFF the equalizer- this is recommended by Apple. Apple says that turning Off the equalizer will help in saving battery life.
12) iPhone charging tip- whenever the iPhones are charged using computer and using wall socket be sure that you don’t connect you phone to a hub/bridge connect to USB socket. Connect it directly to one of your computer’s USB ports.
I hope the 12 iPhone Battery Tips above could help you to save your iPhone Battery Life more longer than before.